What should all students know about the physical sciences? Why should all students have a basic understanding of these ideas? An amazing number of new scientific breakthroughs have occurred in the last 20 years that impact daily lives. This article focuses on the "Next Generation Science Standards" (NGSS) disciplinary core ideas in physical science, the development of those ideas across time, the importance of blending core ideas with scientific and engineering practices to build understanding, and the development of performance expectations.